1. Field of the Invention
The present invention relates to a roller conveyor device adapted to convey a conveyed object such as a metal mould of a press machine and the like through a plurality of rollers on which the conveyed object is placed and also to a scraper for a roller for use in the roller conveyor device.
2. Prior Art
As such a roller conveyor device, conventionally has been known the one shown both in a vertical sectional view of FIG. 6 and in a plan view of FIG. 7 and known by inventors of the present invention.
That is, a plurality of rollers 107 are arranged fore and back in parallel between a left and a right support walls 116, 116 extending in the fore and back direction. Each roller 107 is rotatably supported between both the support walls 116, 116 in such a state that an upper portion of its outer peripheral surface is projected above the upper surfaces of the support walls 116, 116. The symbol S designates a conveyance surface for the metal mould and so on. Between both the support walls 116, 116 there are provided intermediate scrapers 121 on the fore side and the back side of each roller 107 respectively and end scrapers 122.
The intermediate scraper 121 has a base block 141 having a reversed U-shaped cross section. The base block 141 is fixedly secured to respective through-holes 143, 143 of the support walls 116, 116 through two spring pins 142, 142. Fore and back scraper members 144, 144 are fixedly secured onto the upper surface of the base block 141 through a press plate 145 by means of four bolts 146. Also the end scraper 122 is constructed similarly to the intermediate scraper 121.
There are, however, the following problems associated with the above-mentioned conventional construction.
(a) It takes much trouble for installation of the scrapers.
The work for installing the intermediate scraper 121 are to be carried out according to the following steps (1) through (5).
(1) Firstly, the base block 141 is inserted between the support walls 116, 116 from above.
(2) Then, an insertion level of the base block 141 is decided in accordance with the height position of the through-holes 143, 143.
(3) Under this condition, the spring pins 142, 142 are inserted through both the respective through-holes 143, 143 and the base block 141 so that the base block 141 can be fixedly secured to the support walls 116, 116.
(4) The scraper members 144, 144 are placed onto the upper surface of the base block 141.
(5) The scraper members 144, 144 are fixedly secured onto the base block 141 by means of a plurality of bolts 146 under the pressed condition by the press plate 145.
As mentioned above, since at least five steps are required for installing the scraper 121 between the support walls 116, 116, it takes much trouble for such installation.
(b) It takes much trouble for adjusting a scraper frictional resistance (referred to as a scraper resistance hereinafter).
Since the aforementioned scraper 121 comprises five kinds of component members such as the base block 141, the spring pin 142, the scraper member 144, the press plate 145 and the bolt 146, dimensional errors can't help being accumulated after completion of their assembly. As a result, in case that they are merely assembled, there might be provided a scattering in the scraper resistance applied from the scraper member 144 onto the roller 107 and a fine adjustment might be required for locating the scraper member 144 in place. Therefore, it takes much trouble for the adjustment work of the scraper resistance.
Incidentally, the aforementioned problems (a) and (b) are similarly associated with the end scraper 122, too.